" comment key map:
nmap ** <Esc>:.s!^\(\s*\)\(.*\)$!\1// \2!<CR>==
vmap ** :s!^\(\s*\)\(.*\)$!\1// \2!<CR>==
nmap && <Esc>:.s!\(\s*\)//\(.*\)$!\1\2!<CR>==
vmap && <Esc>:s!\(\s*\)//\(.*\)$!\1\2!<CR>==
